The grass snake (Natrix natrix) is Britain's longest snake, reaching lengths of more than 120cm. There have been reports that a grass snake was captured in the Cornwall area and it measured 200cm; if this is true, a snake of this size would be very impressive!
They are olive in colour and unlike the adder the grass snake does not have a zig-zag pattern, instead it has small dark scales evenly dotted down its entire length. The eye is orange and has a circular black pupil. Grass snakes can be found around water sources and it's not uncommon to see them swimming in ponds and lakes. They can stay submerged for up to anhour and are also referred to as ringed snakes as under water their dark scales look like rings.
They are non-venomous so they have to bite and reticulate their prey, squeezing it to death before swallowing it. They do however have a very unique defence mecanism. If under attack, or if this snake feels it has no means of escape they will squirt a foul smelling liquid from their anal gland. If this fails to deter the predator they will feign death; squirming around until they come to rest upside down with their tongue hanging out. Coupled with the foul stench, they look and smell dead and this can give them enough time to escape.